The present invention relates to analyte test strips and meter devices used with these test strips. The invention also relates to health monitoring.
Test strips, such as those used in the current invention, are used to measure the amount of certain analytes in a biological sample, generally using electrochemical reactions. Test strips are well known to one of ordinary skill in the art and are described, for example, in U.S. Pat. Nos. 5,352,351; 5,565,085; and 5,628,890, and US Pat. Pub. 2005/0258035. All references cited in the present disclosure are incorporated herein by reference for all purposes. Small disposable electrochemical test strips are frequently used in the monitoring of blood glucose by diabetics. The test strip is combined with a sample such as blood before or after insertion in a reusable meter, which contains the mechanisms for detecting and processing an electrochemical signal from the test strip into an indication of the presence/absence or quantity of the analyte determined by the test strip. See U.S. Pat. No. 7,344,626 which is incorporated herein by reference.
Because some test strips vary from batch to batch, some models require the user to enter in a code found on the vial of test strips, or insert a chip that comes with the test strip. By entering the code or inserting the chip into the glucose meter, the meter will be calibrated to that batch of test strips. However, if this process is carried out incorrectly, the meter reading is quite inaccurate. The implications of an incorrectly coded meter can be serious for patients actively managing their diabetes. For miscoded meters, the probability of making an insulin dose error of 2 units is 50%. The probability of making an insulin dose error of 3 units is 24%, compared to 0.49% when using a no coding meter. (Significant Insulin Dose Errors May Occur if Blood Glucose Results are Obtained from Miscoded Meters, Charles H. Raine III, et al., 1 J. OF DIABETES SCIENCE AND TECH. 205 (March 2007). This places patients at increased risk of hypoglycemia. In order to reduce user error and decrease testing time, some test strips are now “no-code.” This is done by designing the test strips such that they communicate with the meter and transmit calibration infoimation with no need for user interaction. See, e.g. US Pat. Pubs. 2008/0237040 and 2005/0258035, which are incorporated herein by reference.